Apparatus for coiling lamp filament supports

ABSTRACT

The apparatus comprises a coiling spindle having an axial passageway for periodic movement therethrough of a filament containing a mandrel. The free end of a supply of support wire is temporarily clamped in a slot at the periphery of the spindle which has a die at its end face such that, upon rotation of the spindle, the wire is coiled first around the periphery thereof and then around a generally spiral track in said end face and then down between turns of the filament. A reversing finger member then urges the wire back in the opposite direction to form a locking overwind which is then severed from the supply of support wire. A pressure finger member is then pressed against the outer helical turns on the spindle to partially set the turns and minimize opening or offsetting thereof relative to the filament.

United States Patent [1113556169 I 5 ,S,9 93 5/ Kirnhall 140/7 1 .6 setting thereof relative to the filament.

72 lnventor Joe B. Yoder 3,442,302 5/1969 Brady; et 5:; Tia/7T3 Mayne fights, Ohm Primary Examiner-Lowell A. Larson. PP 798,979 Attorneys-Otto Tichy, Henry P. Truesdell, Frank L.

filled t d f i3 Neuhauser, Oscar B. Waddell and Melvin M. Goldenberg ate 6 an.- H..- a. i. .h .v.,. l j H. [73] Assignee General Electric Company acorporation of New York w- M -M I ABSTRACT: The apparatus comprises a coiling spindle hav- [54] APPARATUS FOR COILING LAMP FILAMENT ing an axial passageway for periodic movement therethrough of a filament containing a mandrel. The free end of a su l of SUPPORTS support wire is temporarily clamped in a slot at the pe ghiry m p v 46mins 11 Drawing gs. of the spindle which has a die at its end face such that, upon [52] US. Cl l40/7l.6 rotation f the spimfle, the wire is m first argmnd the [51] InLCI. B2" 15/04, periphery thereof and then around a generally spin" track in Bums/0.0 said end face and then down between turns of the filament. A [50] Field of Search l40/7L5, revel-Sing finger member then urges the wire back in the 'posite direction to form a locking overwind which is then severed from the supply of support wire A pressure finger [56] References member is then pressed against the outer helical turns on the UNITED STATES PATENTS spindle to partially set the turnsand minimize opening or off- APPARATUS FORCOILING LAMP FILAMENT SUPPORTS BACKGROUND OF THE INVENTION Support members of the type described above have been used with good results ina now well-knowntungsten-halogentype of lamp which comprises an elongated tubular envelope having an axially extending filament which is supported from the envelope wall by engagement therewith of the helical outer turns of such support memberslocated at spaced points along the filament. Such supports. and a coiling spindle or mandrel for winding and installing these supports on the filament are shown in1U.S. Pat. No. 3,168,670 to V. C. Levand, Jr. However, that particular form of spindle requires that the support wire be cut atthree points which results in a wastage of wire which is generally made of tungsten.

Other forms of support-forming and -installing apparatus have been proposed which require two cuts or only a single cut. However, in those devices the opening for the filament coil is located eccentrically in the coiling spindle and reliance is placed on the smaller filament-engaging turns shifting to a concentric position relative to the larger outer turns upon severing of the finished support from the supply of support wire.

SUMMARY OF THE INVENTION It is an object of this invention toprovide apparatus for coiling a support wire memberof the type referred to above which require but a single cut, and .willresult in a minimum of spring back and verylittle, if any, offsetting of the small inner turns relative to the large outer tum or turns. To that end,,the improved apparatus winds the larger and small turns concentricallyand provides for setting the turns in a manner to effectivelyovercome undue spring back or offsetting of the coil turns.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view, on an enlarged scale, of one end of an incandescent lamp having filament supports made by apparatusaccording to theinvention;

FIGS. 2 and 3 are side and front end elevations, respectively, and on .a reduced scale, of apparatus comprising the invention;

FIG. 4 is a vertical section,,on an enlarged scale,.of a winding head chuck assembly including coiling; spindle and associated filament-holding and support-wire locking elements;

FIG. 5 is a fragmentary perspective view, on an enlarged scale, of the front ends of the coiling spindle, and the associated nosepiece of a locking chuck in their relative angular positions for receiving the free end of a support wire;

FIG. 6 is a fragmentary side view of the coiling spindle with the nosepiece removed for greater clarity;-

FIGS. 7 and 8 are fragmentary front end and side views, respectively, of the nosepiece;

FIGS. 9 and 10 are fragmentary front views of the coiling spindle and nosepiece at the start and end, respectively, of the support wire coiling process; and

FIG. 11 is a fragmentaryperspective view of thecoiling spindle,'nosepiece and pressure finger at the end of the coiling operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, thereisshown one end of a tungstenhalogen-type lamp comprising an envelope 1 of quartz or other transparent vitreousmaterialof high softening point, 1

and containing an elongated helically coiled tungsten filament 2 having a straightened end portion extending into a pinch seal cordance with the present invention. The envelope 1 may,in a typical case, be of about three-eighths or one-halfinch outside diameter.

Referring particularly to FIGS. 4 and 2, the assembly of helically coiled filament 2 onits mandrel 7 is inserted into a winding head chuck assembly 8 which is carried by a hollow shaft 9 which is journaled for rotation in a pair of uprights l0 and 11 on a base member 12. The chuck assembly 8 is rotated by a pinion 13 which is fastened to shaft 9 and which is driven by a large gear 14 which is mounted on a drive shaft 15 which is also journaled in uprights 10 and II. For the forming of each filament support 6, the shaft ll5 may be rotated a predetermined controlled amount, for example a single revolution, by a well-known electric motor and timer assembly (not shown).

The filament coil 2 extends through an axial opening or passageway 16 (FIG. 5) in a spindlel'l and is locked in position during forming ofa support 6. by a collet 18 (FIG. 4). The spring finger portions of the collet are held normally closed by being pressed against the tapered endll9 of the enlarged axial opening 20 by a spring-loaded tube 21 which extends through the interior of shaft 9.'The spring 22 acting on tube 21 may be. as illustrated in FIG. 2, anchored at one end to upright10 and attached at its other end to a lever 23 which is pivoted on a pin in an arm 24 attached to upright 10. The lever23 is suitably connected to tube'2l to normally urge it to the right in FIGS. 2 and4, and may be provided with a handle 25 to move tube 21 to the left and thereby release the grip of collet 18 on filament 2 when it is desired to move the filament forward periodically for attachment of additional support members 6 thereto.

The winding head chuck assembly 8 further includes a locking chuckassembly 26 which includes a cylindrical sleeve portion 27 surrounding the enlargedend of shaft 9, and .a nosepiece 28. fastened to the front end thereof by-bolts 29: The nosepiece 28 has an'axial opening 30-which closely fits the peripheral surface of the reduced end 31 (FIGS. 4, 5 and 6) of the spindle 17. The nosepiece 28 further has an annular front end face 32 (FIGS. 4, 5, 7 and 8) of helical pitch-with a sharp shoulder 33 defining. the beginning and the end of the helical surface. The shoulder 33 extendsacross the annular end face 32 (FIGS. 5 and 7) at an angle such that its innerend is at the axial opening 30 and adjacentto the back end .ofa generally tangential slot 34 (FIGS. 5, 6 and '9) t in .the peripheral surface 31 of the spindle 17, at a givenrotational position of the nosepiece 28 of the locking chuck 26.

tion 27 of locking chuck 26. Thereby,the spindle "is at all times locked: to the shaft'9 in predetermined axialnrelationito thenosepiece28, and the locking chuck 26 also rotates-with the shaft 9 whenthe head of the setscrew 35is1held at one end of the arcuate slot 36 by virtue of the action of a torsion spring 37 which has one end 38. anchored in the sleeve 27,8fldith6 other end 39 held against the shoulder 40 of .azreduceddiameter portion of a collar 41 which is locked'toshaft 9 by asetscrew 42. The arcuateslot 36 is of short angularextent such that the locking chuck 26 can be rotated clockwise, as seen-in FIG. 9, sufficiently so thatthe shoulder 33 on -nosepiecei28 makes an acute angle with, and exposes, the 'slot'34 for reoeption of the end of a length of support wire-43-which is-pushed along said shoulder 33 intothe slot 34, after which the chuck 26 is released and rotatescounterclockwise-so that the inner end of theshoulder 33 clamps the end of the wire 43 in the slot 34 to begin the supportwire-forming cycle.

The supplyof support wire 43 (FIG. 2.) is carriedon a:spool 44 which is mountedforrotation about a shaft 45 carried by a third upright 46. The spool is preferablyprovided with a conventional brake which applies tension to the wire 43 during winding of asupport, and prevents overrunning of the spool when rotation of spindle 17 is stoppedl. The wire 34 passes through an aperture in arodlike support member. 47 which is mountedon upright 11.

As indicated above, to start the formation and installation of a support wire member 6, the locking chuck 26 is rotated relative to spindle 17 by grasping the sleeve portion 27 and turning it clockwise (FIG. 9) until the end of the arcuate slot 36 (FIGS. 2 and 4) engages the head of the setscrew 35, at which time the inner end of the shoulder 33 on the face of nosepiece 28 (FIGS. 5 and 9) is at the end of the slot 34. Then the end of wire 43 extending from spool 44 through support 47, is placed against the shoulder 33 (FIG. 9) and is slid along the shoulder into the end of slot 34. The locking chuck 26 is then released to permit the torsion spring 37 to rotate it relative to the spindle I7 so that the inner end of shoulder 33 rotates in a direction to cover over the slot 34 until it strikes the wire 43 and clamps it firmly in said slot 34.

The drive shaft and gear l4 are then started into rotation to, in turn, rotate pinion l3 and shaft 9 and winding head chuck assembly 8. The rotation of spindle 17, with the cooperation of the helical end face 32 of the nosepiece 28 causes the wire 43 to be coiled helically around the surface 31 of spindle 17 for about one and a half turns 47' (FIGS. 10 and 11) after which the wire begins to ride down on a spiral track portion 48 (FIGS. 5, 9 and 10) of a die at the end face of the spindle to form the spiral portion 48' of the support. The said spiral track portion 48 is interrupted by a straight chordal section 49 to form a straight wire section 49 with sharp bends 50 at the ends thereof. The wire then makes a sharp bend at 51 as it passes around a corresponding sharp bend 52 in the die track as it turns abruptly radially inward at 53.

The support wire then comes down into engagement with the filament mandrel 7 between an adjacent pair of turns of the filament coil 2 (FIG. 11) to form several small diameter turns 54 which are concentric with and between several turns of the filament coil 2. The direction of coiling is then abruptly reversed to form a locking overwind 55 which may consist of one or more turns of large pitch.

The reversal in coiling direction to form the locking overwind 55 is performed by a finger member 56 (FIGS. 2 and 3) on the end of a lever 57 which is pivotally mounted on a pin 58 in a bracket 59 which is supported from the upright 11. A roller 60 at the lower end of said lever 57 rides on an annular face cam surface 61 (FIG. 3) on a cylindrical member 61 mounted on the end of drive shaft 15. The roller 60 is held against the cam surface 61 by a spring 62 which is connected at one end to the pin 63 carrying roller 60, said spring 62 being anchored at its other end to upright 11.

As seen in FIG. 2, the reversing finger 56 is normally located adjacent and to the front of the length of support wire 43 and adjacent the coiling spindle 17. The said finger 56 is abruptly moved to the left in FIG. 2 and across the path of the wire 43 to effect the formation of the reverse locking turn 55 (FIG. 11) by a pivotal movement of a lever 57 as the roller 63 is moved quickly and briefly to the right in FIG. 2 when it is engaged by a steeply inclined rise portion (not shown) on the cam surface 61. The rise portion is of very short extent and is followed by a steeply declining drop portion which quickly returns the finger 56 to its original position. Upon completion of this movement, the support 6 is completely formed, and the wire 43 is cut by the operator close to the filament 2 at the end of the overwind 55 as indicated in FIG. I0.

As illustrated herein the large drive gear makes one complete revolution while the pinion gear 13 may be proporis slidable longitudinally in sleeve on the upright 46, up-.

ward against the end face of the spindle l7 and the larger helical turns 47'. The upper end of the finger member 64 (FIG.

II) has a flat surface 64 matching the end of the nosepiece 28 and a curved surface 66 (FIGS. 10 and II) matching the outer helical turns 47 of the support 6, and when forced thereagainst will wedge in place so as to be supported thereat. As seen in FIG. 11, the pressure finger 64 is moved upward into place by pushing against the enlarged head 67 (FIG. 3) at its lower end. The end of support 6 is next released from behind the locking chuck 26 by a clockwise (FIG. 3) rotation of the chuck 26. and the pressure finger member 64 is pulled very slightly away from the spindle 17. The result of these operations is to free the outer turns 47' of the support 6 so that the spring back thereof unwinds one-half to three-fourths of a turn but restricts the turns 47 to the confined space developing between the curved upper end 66 of the pressure finger member 64 and the reduced end 31 of the spindle I7. Accordingly, the turns 47 do not enlarge greatly during the spring back or relaxing of the support 6, and the small diameter and locking turns 54 and 55, respectively, of the support 6 and the filament coil 2 remain in on center or concentric to the large turns 47.

After the pressure finger member 64 has been completely lowered, the filament coil holding collet I8 is opened by movement of the handle 25 to the left in FIG. 2, and the filament coil 2 is advanced to the right (FIGS. 2 and II) for forming and attachment of the next support.

The supports may be spaced evenly by pulling the filament assembly out far enough so that the last completed support is opposite an upright pointer or marker member 68 (FIG. 2) which is mounted on a rod 69 supported from upright II. If desired, a second marker 70 may be provided for sighting a pair of supports.

Iclaim:

1. Apparatus for producing, from a supply source of resilient wire, a continuous coil support for an elongated filament which is helically coiled about a mandrel, comprising a spindle having an axial passageway therethrough for the longitudinal movement of said filament and mandrel, a die at the end of said spindle having a generally spiral track on its face leading from its peripheral edge and terminating in a generally radial track leading toward toward the said axial passageway, and means to temporarily grip an end of a length of wire at the peripheral surface of said spindle near its edge, drive means carried by said apparatus and operable to cause rotation of said spindle and its die to cause the wire to coil around the periphery of the die and to then follow the spiral track and then the radial track down upon the mandrel between turns of the filament coil for several turns along said mandrel, means for reversing the direction of coiling the support wire over the same portion as is coiled about the mandrel to form a locking overwind, and a pressure finger means mounted for movement toward the end of said spindle and having an arcuate face engageable with portions of the helical turns on the periphery of the spindle to partially set the turns and minimize opening or offsetting thereof.

2. Apparatus as set forth in claim 1 wherein a portion of the said spiral track is interrupted by a straight chordal section to form a corresponding straight wire section with sharp bends in the wire at the ends of said straight section.

3. Apparatus as set forth in claim I wherein the means to temporarily grip an end of a length of wire at the peripheral surface of said spindle near its edge comprises a generally tangential slot in said peripheral surface, and a locking chuck member including a nosepiece surrounding said spindle and rotatable relative thereto and having an axial opening which makes a close fit with said peripheral surface of the spindle, said nosepiece having an annular end face of helical pitch with a sharp shoulder defining the beginning and the end of the.

mounting said reversing finger member for pivotal movement and with an end portion normally located adjacent and to the front of the length of support wire and adjacent the coiling spindle. and means operable at a predetermined instant to pivot said finger rearwardly toward the support wire and across the path thereof to reverse its coiling direction. 

1. Apparatus for producing, from a supply source of resilient wire, a continuous coil support for an elongated filament which is helically coiled about a mandrel, comprising a spindle having an axial passageway therethrough for the longitudinal movement of said filament and mandrel, a die at the end of said spindle having a generally spiral track on its face leading from its peripheral edge and terminating in a generally radial track leading toward toward the said axial passagewAy, and means to temporarily grip an end of a length of wire at the peripheral surface of said spindle near its edge, drive means carried by said apparatus and operable to cause rotation of said spindle and its die to cause the wire to coil around the periphery of the die and to then follow the spiral track and then the radial track down upon the mandrel between turns of the filament coil for several turns along said mandrel, means for reversing the direction of coiling the support wire over the same portion as is coiled about the mandrel to form a locking overwind, and a pressure finger means mounted for movement toward the end of said spindle and having an arcuate face engageable with portions of the helical turns on the periphery of the spindle to partially set the turns and minimize opening or offsetting thereof.
 2. Apparatus as set forth in claim 1 wherein a portion of the said spiral track is interrupted by a straight chordal section to form a corresponding straight wire section with sharp bends in the wire at the ends of said straight section.
 3. Apparatus as set forth in claim 1 wherein the means to temporarily grip an end of a length of wire at the peripheral surface of said spindle near its edge comprises a generally tangential slot in said peripheral surface, and a locking chuck member including a nosepiece surrounding said spindle and rotatable relative thereto and having an axial opening which makes a close fit with said peripheral surface of the spindle, said nosepiece having an annular end face of helical pitch with a sharp shoulder defining the beginning and the end of the helical surface, said shoulder extending across said annular end face at an angle such that its inner end is at the said axial opening and adjacent the back end of said tangential slot at a given rotational position of said nosepiece, and the length of the shoulder makes an acute angle with the length of the tangential slot so that the slot is open for receipt of a free end of the resilient wire advanced along said shoulder and into the end of said slot, and means resiliently urging said nosepiece for rotation relative to the spindle to a clamping position wherein said inner end of said shoulder moves along and over said slot until it engages said wire and clamps it in said slot.
 4. Apparatus as set forth in claim 1 wherein the means for reversing the direction of coiling the support wire to form a locking overwind comprises a reversing finger member, means mounting said reversing finger member for pivotal movement and with an end portion normally located adjacent and to the front of the length of support wire and adjacent the coiling spindle, and means operable at a predetermined instant to pivot said finger rearwardly toward the support wire and across the path thereof to reverse its coiling direction. 